Should be OK as long as you are certain you have the right BIOS image file. Failed BIOS flash is rare but possible; I have had no issues myself in the past 15 years or so.

Heres my latest CPU-Z. My com still freezes or bluescreen randomly even after updating BIOS.

Did you load the BIOS defaults after update?

Memtest does run at boot up, they have bootable CD ISO as well as bootable USB, take your pick, test your RAM one stick at a time, then we do a drive test later.

I'll look at the BIOS screen from the manual.

For now, In the BIOS set your memory to 533MHz (266MHz)
Disable Hyper-Threading for the CPU.
Increase the PCI-E Frequency to 102 from Auto (100)

Still need to change some voltages.

Somehow when i change my PCI-E Frequency to 102, when i go to my bios again later on, it seem to auto reset back to Auto(100). I'm currently using Core2Duo 6600, there's no hyper-threading.

By the way, heres my latest minidump

There is a section in the BIOS that has to do with Hyper-Threading, Make sure it is disabled. We know Core 2 Duo and Quad are not Hyper-Threading CPUs.

How about the Memory to 533MHz, did you do that before we do Memtest?

PCI-E requires a voltage boost at the same time to one of the bridges, I have to look at the BIOS section in your manual.